Question

Occasionally, my IIS 6 server will receive a request which contains a space after “.aspx”, like:
http://www.foo.com/mypage.aspx%20?param=value

The “%20” immediately following “.aspx” causes the server to result in a “404 Page Not Found”.

Is there a way to configure IIS to accept “.aspx%20” and process the page as if the “%20” didn’t exist?

I looked at the “Home Directory” / “Configuration” in the properties of the site in IIS Manager and I added an entry for “.aspx%20” but that didn’t work. Any other suggestions are appreciated.

Answer 1

+1 for the custom HttpModule (as Frédéric Hamidi suggested). It’s a clean, modular solution and may help you rewrite other URLS, should you need to do so.

Your OnBeginRequest (referring to the link Frédéric provided) might look more or less like this:

private void OnBeginRequest(object sender, EventArgs e)
{
   HttpContext context = ((HttpApplication)sender).Context;
   string url = context.Request.RawUrl;
   context.RewritePath(url.Replace(".aspx%20",".aspx"), false);
}